Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

[safe/jmp/linux-2.6] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 8ebbfdf..ac7031f 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1234,6 +1234,20 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
        return blkdev_ioctl(bdev, mode, cmd, arg);
 }
 
+/*
+ * Try to release a page associated with block device when the system
+ * is under memory pressure.
+ */
+static int blkdev_releasepage(struct page *page, gfp_t wait)
+{
+       struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super;
+
+       if (super && super->s_op->bdev_try_to_free_page)
+               return super->s_op->bdev_try_to_free_page(super, page, wait);
+
+       return try_to_free_buffers(page);
+}
+
 static const struct address_space_operations def_blk_aops = {
        .readpage       = blkdev_readpage,
        .writepage      = blkdev_writepage,
@@ -1241,6 +1255,7 @@ static const struct address_space_operations def_blk_aops = {
        .write_begin    = blkdev_write_begin,
        .write_end      = blkdev_write_end,
        .writepages     = generic_writepages,
+       .releasepage    = blkdev_releasepage,
        .direct_IO      = blkdev_direct_IO,
 };